Copyright
©The Author(s) 2020.
World J Radiol. Jun 28, 2020; 12(6): 87-100
Published online Jun 28, 2020. doi: 10.4329/wjr.v12.i6.87
Published online Jun 28, 2020. doi: 10.4329/wjr.v12.i6.87
Table 1 Echocardiographic parameters to evaluate for cardiac amyloidosis, modified from expert consensus recommendations[5]
Parameters |
Left ventricular size and ejection fraction |
Left ventricular wall thickness |
Myocardial echogenicity |
Diastolic function |
Left ventricular longitudinal strain (global and regional bull’s eye distribution) |
Atrial size and function |
Interatrial septum |
Estimated right ventricular systolic and right atrial pressures |
Valve thickness |
Pericardial effusion |
Table 2 Magnetic resonance imaging evaluation of cardiac amyloidosis, modified from expert consensus recommendations[5]
Protocol | Parameters |
Steady state free precession cine imaging | Left ventricular size, stroke volume, ejection fraction, wall thickness, mass (without and with indexing), atrial size and function, pericardial effusion |
Phase-sensitive inversion recovery for delayed contrast imaging | Late gadolinium enhancement |
T1 imaging | Native T1 mapping pre-contrast, T1 inversion time scout, extracellular volume post-contrast |
T2 imaging | T2 mapping, edema imaging |
Imaging considerations | Parameters |
Patient and equipment preparation | |
Patient preparation | No prerequisites, no fasting |
Position | Supine arms above shoulder or supported |
Scan | Rest scan |
Dose | 11C-PiB 10-20 mCi (370-740 MBq) IV[50] |
18F florbetapir 6 mCi (222 MBq) IV[51] | |
18F florbetaben 0.1 mCi/kg (4 MBq/kg) IV[52] | |
Time from injection to acquisition | 11C-PiB 30 min[50] |
18F florbetapir continuous over 60 min[51] | |
18F florbetaben continuous over 80 min[52] | |
Scan parameters | |
Field of view | Heart; Chest |
Image type | Low-dose (10 mA, 120 kVp, free tidal breathing) CT scout scan |
Low-dose CT transmission scan (10 mA, 120 kVp, free tidal breathing) over the heart | |
Emission scan 2D 40-60 mCi (1480-2220 MBq) | |
Emission scan 3D 10-20 mCi (370-740 MBq) | |
Matrix | 128 × 128-400 × 400 |
Reconstruction | Filtered back projection or iterative reconstruction |
Table 4 Contemporary diagnostic criteria for cardiac amyloidosis, modified from expert consensus recommendations[61]
Category | Criteria |
Endomyocardial biopsy | Apple-green birefringence with Congo red staining and polarized light, immunohistochemistry and/or mass spectrometry typing confirmed |
Extracardiac biopsy | ATTR: Biopsy proven and typical imaging findings |
AL: biopsy proven and typical imaging features or abnormal cardiac biomarkers (N-terminus B-type natriuretic peptide or troponins if other causes excluded) | |
Non-biopsy (or ATTR) | Grade 2 or 3 myocardial uptake of radiotracer |
Serum free light chains, serum and urine immune-fixation not finding clonal plasma cell process | |
Typical imaging findings | |
Typical imaging findings: echocardiography | Left ventricular wall thickness > 12mm |
Relative apical sparing of left ventricular longitudinal strain ratio (apical average/basal and mid average > 1) | |
Grade 2 or higher diastolic dysfunction | |
Typical imaging findings: magnetic resonance imaging | Left ventricular wall thickness > upper limit normal for sex |
Global extracellular volume > 0.40 | |
Abnormal gadolinium kinetics, myocardial nulling prior to blood pool nulling or difficulty in nulling the myocardium because of diffuse amyloid infiltration | |
Diffuse, subendocardial or patchy late gadolinium enhancement patterns may be observed | |
Typical imaging findings: Positron emission tomography | 18F-florbetapir or 18F-florbetabem |
Left ventricular myocardium to blood pool ratio > 1.5 | |
Retention index > 0.030/min |
Table 5 Strengths and limitations of each imaging modality for assessing cardiac amyloidosis
Modality | Echocardiography | Magnetic resonance imaging | Nuclear imaging |
Strengths | Availability and portable | Lack of radiation | Distinguishing between AL/ATTR |
Low cost | High spatial resolution | ||
Lack of radiation | Chamber quantification | ||
Lack of contrast | Tissue characterization | ||
Chamber quantification | Quantifying myocardial fibrosis | ||
Diastolic function | |||
Strain | |||
Weaknesses | Variable spatial resolution | Higher cost | Higher cost |
Low specificity | Availability may be limited | Availability may be limited | |
No tissue characterization | Gadolinium-based contrast administration | Radiation exposure | |
Not distinguish AL/ATTR | Claustrophobia | ||
Not able to assess and quantify myocardial fibrosis | Metallic device | ||
Not able to distinguish between AL/ATTR |
- Citation: Wang TKM, Abou Hassan OK, Jaber W, Xu B. Multi-modality imaging of cardiac amyloidosis: Contemporary update. World J Radiol 2020; 12(6): 87-100
- URL: https://www.wjgnet.com/1949-8470/full/v12/i6/87.htm
- DOI: https://dx.doi.org/10.4329/wjr.v12.i6.87